triangle :: [[Int]]
triangle = [
	[75],
	[95,64],
	[17,47,82],
	[18,35,87,10],
	[20,04,82,47,65],
	[19,01,23,75,03,34],
	[88,02,77,73,07,63,67],
	[99,65,04,28,06,16,70,92],
	[41,41,26,56,83,40,80,70,33],
	[41,48,72,33,47,32,37,16,94,29],
	[53,71,44,65,25,43,91,52,97,51,14],
	[70,11,33,28,77,73,17,78,39,68,17,57],
	[91,71,52,38,17,14,91,43,58,50,27,29,48],
	[63,66,04,68,89,53,67,30,73,16,69,87,40,31],
	[04,62,98,27,23,09,70,98,73,93,38,53,60,04,23]
	] 
euler_018 = head $ foldr1 g triangle
	where
		f :: (Num a, Ord a) => a -> a -> a -> a
		f x y z = x + ( max y z )
		g :: (Num a, Ord a) => [a] -> [a] -> [a]
		g xs ys = zipWith3 f xs ys (tail ys)